Steam-boiler furnace.



Patented Aug. 22, I899.

.1. MILTQN. STEAM BOILER FURNACE.

(Application filed Apr. 14, 1899.)

3 Sheetg-Sheet I,

(No Model.)

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Patented Aug. 22, I899.

J. MILTON.

STEAM BOILER FURNACE.

(Application filed Apr. 14, 1899.)

3 SheetsSheet 2.

(No Model.)

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No. 63!,528. Patented Aug. 22, I899.

.1. MILTON. STEAM BOILER FURNACE.

(Application filed Apr. 14, 1899.) (No Model.) 3 Sheets-Sheet 3.

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UNITED STATES PATENT O EICE.

JOHN MILTON, OF WASHINGTON, DISTRICT OF COLUMBIA, A ssleNon TO THE AMERI N LOOOMOTIVE APPLIANCE COMPANY, OF VIRGINIA.

STEAM-BOILER FURNACE.

SPECIFICATION forming part of Letters Patent No. 631,528, dated August 22, 1899.

Application filed April 14, 1899. Serial No. 712,994. (No model.)

To all whom it may concern:

Be it known that 1, JOHN MILTON, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Steam-Boiler Furnaces; and I do declare the following to be a full, clear, and exact description of.the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference'being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to steam-boiler furnaces and is directed to improvements inthe exhaust regulating attachment, for which Letters Patent No. 590,846 were granted to me on or about the 28th day of September, 1897.

My present invention, which is more particularly concerned with furnaces of locomotive-engines, contemplates the provision of an inlet adjacent to the stack, through which air in controllable quantity is admitted for the counteraction of the influence of the airblast occasioned by opening the furnace-door, and also for overcoming the effects of excessive exhaust produced while the engine is being started or is moving slowly up a heavy grade or when the driving-wheels slip in rotation, in all of which cases the exhaust is from a wide-open .valve and with practically full boiler-pressure. The effects of the exhaust under the cited conditions are to tear the fire and disintegrate the fuel to such an extent as to produce by the forcible intermittent draft thus created emissions of sparks and Cinders which, aside from the danger and discomfort attending their formatibmaccomplish by their exclusion from the furnace a very material loss of heat and consequently power. These enumerated difficulties are practically overcome by the construction set forth in my above-referred-to patent, the invention which forms the subject-matter thereof consisting, broadly considered,'of a valved air-inlet adjacent to the stack, means for automatically Controlling the inlet coincidently with the manipulation of the stoking-door, and a valve carried by and normally closing an opening in the aforesaid valve, adapted to be actuated 'valve, and valve-operating means.

by external air-pressure. This valve, which is described as being carried by the inletvalve, operates more or less successfully to admit air to counteract the injurious eifects of the excessive exhaust produced under the extraordinary conditions named, but owing to certain prerequisites as to the volume of air necessary to be admitted I have found that as an essential to the accomplishment of the most desirable results this air-opening must be of comparatively large area, and inasmuch as its location in the inlet-valve would necessitate enlargement of the latter to an extent disproportionate to its surroundings it is my purpose to so modify the construction and arrangement of parts as to enable the inlet-valve to perform the double function of admitting air to counteractthe effect of the exhaust and to overcome the influence of the ingress of air through the open furnacedoor. The mechanism by which this highlydesirable result is accomplished is set forth in detail in the following description, which is to be read in connection with the accompanying drawings.

In the drawings, Figure 1 is a side elevation, partly in section, of a locomotive-engine embodying my invention. Fig. 2 is a rear end elevation. Fig. 3 is a fragmentary top view. Figs. 4 and 5 are respectively enlarged detail side and central sectional views of the door of the smoke-box, showing the air-inlet, Fig. 6 is an enlarged View in elevation of-the front of the smoke-box with the number-plate removed. v

Referring to the said drawings by letter, A denotes the fire-box of a locomotive-engine. B is the boiler, and C the smoke-box or extension-front, these parts being of the usual construction and needing no description, ex-

cept that the fire-box has the usual door a,

cis located a sufficient distance therefromto allow of the admission of air in proper quantity. On the inner side of the door, around the opening (Z, is secured a ring (P, the inner face of which forms a seat for the valve F, said valve being pivoted at its lower side to open inwardly. Any suitable pivotal connection for the valve may be provided; but I prefer the construction shown, which consists of ears (1 and f, formed, respectively, on the ring and valve, and a pintle F, passed through said ears. The valve is made to rest closely against its seat when in closed position to render the smoke-box at this point approximately air-tight under normal conditions. On the outer side of the door, adjacent to the lower side of the opening, is secured a bracket 1, having ears g, which support a rod 7t. Pivoted on this red is a lever t'. the upper arm 1" of which has link connection with the valve, while its lower arm 2' is connected by a rod i with the upper arm j of a second lever j, pivoted to a post j secured to and extending outwardly from the door (Z. The lower end j of the lever 7' is free and is provided with a lateral projection j". Pivoted on the post 7' immediately to one side of the leverj, is an arm is, which in one direction abuts against the projectionj". The outer end of this arm is connected by a rod Zwith the stoking-door a, the movement of which controls, through the connections just described, the movement of the valve F, as will presently be more fully explained.

The normal closed position of the valve is effected by the action of right and left coiled springs m on, each of which is connected at one end to the lever i and at the other end to an adjusting-nut m, by which the tension of the springs may be varied. The valve is thus opened against the action of springs, the tension of which may be so delicately adjusted as to render the valve exceedingly sensitive to the action of the exhaust, which operates through the external air pressure or impact to move the valve inwardly to uncover the opening and admit the proper quantity of air to neutralize the tendencies of the exhaust when, as before stated, the engine is being started or is moving slowly up a heavy grade or when the driving-wheels slip in rotation. The operation of the valve under the action of the exhaust is thus entirely automatic, and the quantity of air admitted past the valve is governed entirely by the force of the exhaust under the extraordinary conditions stated. This excessive exhaust is only temporarily occasioned, and the automatic operation of the valve, and consequently the admission of the air to counteract the injurious effects which would otherwise be produced, depends entirely upon this increased strength or power of the exhaust. It may be here stated that should there be an improper adjustment of the engine-valves, and consequently a relative variation in the successive exhausts from the cylinder, the air-valve may be employed to indicate by its irregular movements such fault in adjustment and to aid in remedying the defect.

The automatic operation of the valve under the action of the exhaust is entirely distinct from the operation of the valve to control the inlet coincidently with the manipulation of the stoking-door. In the automatic movement of the valve to uncover the opening or air-inlet the leverj is rocked, and its lower arm j, which carries the projection, is moved independently of the arm k. In operating the valve by the movement of the stoking-door, however, the lever j is, by the engagement of the arm 7t with the projection j, rocked with said arm, and through the described connection with the valve the latter is opened against the action of the springs m, admitting air in proportion to the volume of air entering the stoking-opening. The connection between the rod land the door a may be substantially that shown in my patent above referred to, the pintle a of the doorhinge carrying an arm 02., which is connected by a rod a to one of the arms of a bell-crank lever 0-1 the other arm having direct connection with rod Z.

The door d of the smoke-box carries a partition 0, extending from the base to a point about centrally of the valve F. This partition is employed to keep the valve free from cinders, and also to deflect the air entering the inlet toward the stack and away from the accumulation of cinders in the smokebox. Above the partition is a screen 0, which serves, with the partition, to keep the interior of the door free from cinders. Any fine cinder which finds its way into the door may be removed through a hand-hole, shown as closed by a cover 19.

My invention in its broadest sense consists in the provision of an air-inlet adjacent to the stack of a steam-boiler furnace having an exhaust-draft, a valve at said inlet operated automatically under the action of excessive exhaust to admit air for the counteraction of the tendencies of such excessive exhaust, and means independent of the exhaust for operating said valve coinciden tly with the manipulation of the stoking-doorto admit air through the inlet for the counteraction of the eiIect of the air-blast in the opening of the door during stoking and manipulation of the fire. This air-inlet and the valve therefore may be located at any desired point which is in suflieiently close proximity to the stack and exhaust to secure the desired results; but for economy of construction and facility of installationI prefer that the opening, the valve, and the valve-operating means be applied to the door of the smoke-box, as shown, whereby not onlycan the invention be readily attached to existing furnaces, but in the case of locomotive-engines, where access to the smoke box must frequently be had, the device being carried by the door affords no obstruction to such access when the latter is opened.

My invention,,while applicable to steamboiler furnaces of the character abovenamed, is more especially designed for use in connection with locomotive-boiler furnaces, the same, in addition to regulating the draft and relieving the exhaust under the conditions stated, operating to prevent the formation of sparks and cinders, and thereby to avoid the danger of firing adjacent property and insure comfort to the occupants of thetrain. In addition by the use of my improved appliance not only is there a great saving of fuel, but also in the time and labor incident to the manipulation of the fire, as the bed of fuel is not subjected to the tearing and disintegrating action of sudden strong drafts through the grate induced by the excessive exhausts.

I claim asmy invention- 1. In a steam-boiler furnace of the character described, an air-inlet adjacent to the furnace-stack and exhaust-outlet, a self-closing valve at said inlet openable under the action of excessive exhausts, and means independent of the action of the exhaust for opening said valve coincident] y with the manipulation of the stoking-door.

2. In a steam-boiler furnace of the character described, an air-inlet adjacent to the furnace-stack and exhaust-outlet, a springcontrolled valve at said inlet openable under the action of excessive exhaust, and means.

independent of the action of the exhaust for opening said valve coincidently with the manipulation of the stoking-door.

3. In asteam-boiler furnace of the character described, a chamber between the boilerfiues and stack, a door closing said chamber having an opening providing an air-inlet, a spring-controlled valve at said opening carried by the door and openable under the action of excessive exhausts, and means independent of the action of the exhaust for opening said valve coincidently with the manipulation of the stoking-door.

4. In a steam-boiler furnace of the character described, a chamber between the boilerfiues and stack, a door closing said chamber having an opening providing an air-inlet, a spring-controlled valve hinged to the door and controlling said inlet and openable under the action of excessive exhausts, and means located without the chamber operating independently of the action of the exhaust to open the valve coincidently with the manipulation of the stoking-door.

5. Ina steam-boiler furnace of the character described, a chamber between the boilerfiues and stack, a door closing said chamber. having an opening providing an air-inlet, a valve for said inlet hinged to-the door and openable against the action of a spring by excessive exhausts, a lever operatively connected with the door and provided with a projection, and an arm operatively connected .with the stokingdoor and adapted when moved in one direction coincidently with the movement of the latter to engage the projection on the lever and open the valve.

6. In asteam-boiler furnace of the character described, a chamber between the boilerflues and stack, a door closing said chamber having an outer Wall provided with an opening afiording an inlet for air, and an inner Wall perforated in its upper portion, aspringcontrolled valve hinged to the front wall and normally closing said opening, said valvebeing openable under the action of excessive exhausts.

In testimony whereof I affix my signature 

